Astronomers have discovered an infant solar system that appears to be the youngest still-forming solar system yet found. The baby star, which is more than 450 light-years from Earth in the constellation Taurus, is encircled by a swirling disk of dust and gas.
The National Radio Astronomy Observatory in Virginia reports that that baby star currently has about one-fifth the mass of the Sun. Scientists expect, however, that the infant star will probably pull in material from its surroundings to eventually equal the Sun’s mass. In fact, the disk of dust and gas surrounding the young star holds at least enough mass to create seven Jupiters.
“This very young object has all the elements of a solar system in the making,” said John Tobin, of the National Radio Astronomy Observatory.
Astronomers at the NRAO utilized the Submillimeter Array and the Combined Array for Millimeter-wave Astronomy to examine the baby star, called L1527 IRS, living in a humble abode called the Taurus Cloud.
Astronomers believe that the young solar system is no more than 300,000 years old, compared to the 4.6-billion-year age of our Sun and its planets.
“It may be even younger, depending on how fast it accumulated mass in the past,” Mr. Tobin said.
Astronomers hope to study the infant star to learn more about star formation. They believe that the young star is one of the best examples of the earliest state of star formation. Using the millimeter-wave observatories, astronomers found both dust and carbon monoxide around the object. They also became the first astronomers to conclusively demonstrate that the infant star is encircled by a rotating disk of material, and the first to be able to calculate the mass of the protostar itself.
By measuring the Doppler shift of radio waves emanating from carbon monoxide in the disk, astronomers were able to demonstrate that the rotation speed in the disk changes with the material’s distance from the star in the same way that the orbital speeds of planets change with distance from the Sun.
Keplerian rotation “marks one of the first essential steps toward forming planets, because the disk is supported by its own rotation, will mediate the flow of material onto the protostar and allow the planet formation process to begin,” said Hsin-Fang Chiang of the University of Illinois and the Institute for Astronomy of the University of Hawaii.
“This is the youngest protostar found thus far to show that characteristic in a surrounding disk,” Mr. Tobin added. “In many ways, this system looks much like we think our own Solar System looked when it was very young.”
Observations from the Gemini Observatory were the first to suggest the presence of a large disk encircling the protostar, but Mr. Tobin and his team were the first use high-resolution millimeter-wave observations to verify the presence of the disk and calculate its rotation.
Next, astronomers plan on using the Atacama Large Millimeter Array (ALMA) to better understand the baby star.
“ALMA’s advanced capabilities will allow us to study more such objects at greater distances,” Mr. Tobin posted. “With ALMA, we will be able to learn more about how the disks form and how quickly the young stars grow to their full size, and gain a much better understanding of how stars and their planetary systems begin their lives.”